Few groups are more hazardous to public health than the anti-vaccine movement — because there’s a body count affiliated with their actions. When vaccination rates drop, communicable diseases re-emerge, and people suffer. While anti-vaccine sentiment will probably persist as long as vaccines are around, we’re fortunate that vaccination rates, on balance, remain very high. In 2009, U.S. vaccination rates for most childhood vaccines were over 90%. And less than 1% are completely unvaccinated. But do high vaccination rates mean that parents have confidence in the safety and effectiveness of vaccines? Most states and provinces maintain public health regulation that require documentation of vaccination status for school or day care admission. So vaccines may be seen as a requirement or obligation which may override lingering concerns. Do concerns remain? That’s what a recent survey undertook to explore.

I’ve blogged before on antivaccination sentiment, and its drivers. It’s remarkable that viewing anti-vaccination material for even five to ten minutes can increase the perception of risk of vaccination, and decrease the perceived risk of omitting vaccines, leading to lowered vaccination intentions. It tells me that as a health professional, I need to be ready to address vaccines concerns directly, honestly and completely. To do that, I need to be prepared for the common arguments and concerns about vaccinations. The SBM archives are a good resource, serving as a compilation for issues and topics of interest to its authors.

Allison Kennedy, an epidemiologist at the Centers for Disease Control (CDC) and other colleagues at the CDC used a consumer survey of parents to examine intentions, behaviors and concerns about vaccines. The survey also sought to understand common sources for vaccine information.This paper, Confidence about vaccines in the United States: Understanding Patient Perceptions, is unfortunately behind a paywall. So I’ll touch on the highlights of this survey, and what it means for those “in the trenches” of vaccine advocacy.

Kennedy’s analysis is data cut from a large survey on consumer behaviors and intent, the 2010 HealthStyles survey, which included 4,198 households. The analysis was limited only to households with children aged six or younger, shrinking the pool to 376 responses. It’s a small sample size, admittedly, so how representative these data are isn’t clear. In addition, the authors comment that one cannot infer causality: We don’t know if cited concerns preceded or followed vaccination actions.

Intentions

The majority of respondents (94%) intended to vaccinate their child with all recommended vaccines. Only 5% intended to partially vaccinate, and 2% (seven people) intended to leave their children completely unvaccinated. (Number don’t add to 100 because of rounding.) These number look good and seem consistent with the (U.S.) national vaccination goals. Reason to be reassured? Not quite.

Despite an overwhelming majority intending to vaccinate, only 23% reported no concerns about childhood vaccines. The rest reported a number of concerns:

38% — painful to receive so many shots during one visit

36% — too many vaccines at once

34% — too many vaccines during first two years of life

32% — vaccines may cause fevers

30% — vaccines may cause learning disabilities, such as autism

26% — ingredients in vaccines are unsafe

17% — vaccines are not tested enough for safety

16% — vaccines may cause chronic disease

11% — vaccines are given to prevent diseases children are not likely to get

9% — my child will not be vaccinated on time because there’s not enough of some vaccines

8% — vaccines are given to prevent diseases that are not serious

23% — no concerns

This list should look pretty familiar. With the exception of concerns about shortages (which isn’t a negative against vaccines), this is a succinct summary of standard anti-vaccine arguments the contributors to this blog has addressed again and again.

The authors attempted to distill differences in concerns between parents that fully intended to vaccinate their children, and those that stated an intent to reduce or eliminate vaccines. As expected, everyone without concerns intended to fully vaccinate. And as would be expected, there were more concerns among parents who intended to reduce or avoid recommended vaccines. While there were some modest differences in the incidence of some specific concerns between the two groups, the sample size of the latter is too small to draw any meaningful observations.

Sources of Information

Fully 60% of parents sought out “some” or “a lot” of information on vaccine safety prior to any vaccination — not surprising given the movement for patients to become more involved as partners in care decisions. Other people were cited as one of the three most important source of information, including health care professionals (85%), family members (46%) and friends (22%). The internet is a growing source of information, with 24% including it in their top three sources ( I discussed popular sites in a prior post) while traditional media, including television, newspapers, and magazines, are infrequent sources of information. Reassuringly, daytime television was a top information source for less than 1% of respondents, so Dr. Oz, no friend of science, may not have the influence on vaccination that his viewership might suggest.

Most respondents, when asked about their relationship with health professionals, gave generally good evaluations. Over half “strongly agreed” they trusted the advice of their health care professional, while 31% “somewhat agreed”.

Implications

We cannot be complacent when it comes to vaccination rates: Concerns about vaccine safety are prevalent in parents, even among those that intend to complete the vaccination schedule for their children. Clearly, anti-vaccination arguments are resonating, though thankfully they’re not translating into vaccine refusal in most parents. Given the dual importance of both the internet, and personal advice, on vaccine confidence, this survey reinforces the need to be aware of the shifting goalposts from the anti-vaccine movement, in order that we can be prepared to proactively discuss these concerns. Moreover, non-professionals that are familiar with and can address typical anti-vaccine concerns should be able to have a meaningful impact on vaccine confidence.

This paper ultimately left me thinking about the complexity of understanding and addressing vaccine concerns. Parental concerns are far more nuanced than can be summed up in a single confidence parameter. As advocates we need to do a better job of understanding the relationship between attitudes and behaviors, recognizing that simply having the facts available is just on component of maintaining confidence in vaccination.